Polaribacter marinivivus sp. nov., a member of the family Flavobacteriaceae isolated from seawater.

Abstract

A Gram-stain negative, non-flagellated, non-gliding, aerobic and rod-shaped bacterium, designated GYSW-15(T), was isolated from a seawater of Geoje island on the South Sea, South Korea, and subjected to a polyphasic taxonomic approach. Strain GYSW-15(T) was found to grow optimally at 30 °C, at pH 7.0-8.0 and in the presence of approximately 2.0 % (w/v) NaCl. Neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain GYSW-15(T) belongs to the genus Polaribacter, clustering coherently with the type strain of Polaribacter porphyrae showing sequence similarity value of 97.0 %. Strain GYSW-15(T) exhibited 16S rRNA gene sequence similarity values of 94.3-96.4 % to the type strains of the other Polaribacter species. Strain GYSW-15(T) was found to contain MK-6 as the predominant menaquinone and iso-C15:0, iso-C15:1 G, iso-C16:0 3-OH and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) as the major fatty acids. The polar lipid profile of strain GYSW-15(T) containing phosphatidylethanolamine and an unidentified lipid as major components was similar to that of the type strain of P. porphyrae. The DNA G + C content of strain GYSW-15(T) was determined to be 31.2 mol% and its mean DNA-DNA relatedness with P. porphyrae LMG 26671(T) was 17 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain GYSW-15(T) is separated from recognized Polaribacter species. On the basis of the data presented, strain GYSW-15(T) is considered to represent a novel species of the genus Polaribacter, for which the name Polaribacter marinivivus sp. nov. is proposed. The type strain is GYSW-15(T) ( = KCTC 42156(T) = CECT 8655(T)).